Molded catalyst for catalytic gas reactions

Abstract

A molded catalyst for fitting into a reactor vessel having an inlet and an outlet for a reactant gas, the catalyst having openings therethrough parallel to the direction of a reactant gas which is introduced into the reactor vessel from the inlet, the catalyst comprising: a wear-resistant front portion facing the inlet of the reactor vessel, and the remaining portion of the catalyst made so wear-susceptible as to have either: (a) a wearability of 2-10% in a shaking abrasion test wherein grinding particles having an average particle size of 1000 mu m and a Mohs scale of 9 are placed in the openings of the catalyst in an amount of 50% by volume based on the total volume of the openings, and the catalyst is shaken for three hours with an amplitude of 77 mm and a frequency of 320 per minute; or (b) a wearability of 7.5-35% in an air abrasion test wherein an air which contains silica particles having an average particle size of 40 mu m in amounts of 70 g/m3 is passed through in a reactor vessel including a rectangular parallelepipedic catalyst of 45 mm wide, 45 mm thick and 100 mm long so fitted thereinto that the catalyst extends longitudinally in the direction of the flow of the air for 30 min. at a superficial velocity of 40 m/sec. at the front portion of the catalyst.

What is claimed is: 
     
       1. A molded catalyst for fitting into a reactor vessel having an inlet and an outlet for a reactant gas, the catalyst having openings therethrough parallel to the direction of a reactant gas which is introduced into the reactor vessel from the inlet, the catalyst comprising: a wear-resistant front portion substantially facing the inlet of the reactor vessel. and a remaining portion, said remaining portion being so wear-susceptible as to have either: (a) a wearability of 2-10% in a shaking abrasion test wherein grinding particles having an average particle size of 1000 μm and a Mohs scale of 9 are placed in the openings of the catalyst in an amount of 50% by volume based on the total volume of the openings, and the catalyst is shaken for three hours with an amplitude of 77 mm and a frequency of 320 per minute; or   (b) a wearability of 7.5-35% in an air abrasion test wherein an air which contains silica particles having an average particle size of 40 μm in amounts of 70 g/m 3  is passed through in a reactor vessel including a rectangular parallelepipedic catalyst of 45 mm wide, 45 mm thick and 100 mm long so fitted thereinto that the catalyst extends longitudinally in the direction of the flow of the air for 30 min. at a superficial velocity of 40 m/sec. at the front portion of the catalyst.